The present invention relates to a swash plate type compressor in which a rotary motion of a swash plate is converted into reciprocating motions of pistons via shoes interposed between the swash plate and the pistons, and more specifically, to a structure for regulating rotation of each piston so as to prevent contact or engagement between the swash plate and each piston in the swash plate type compressor.
In a swash plate type compressor of this type, there has been a problem that the pistons are rotated about their respective axes so that the pistons contact or engage with the circumference of the swash plate to cause abrasion of the associated members, noise and the like.
For solving the foregoing problem, Japanese First (unexamined) Patent Publication No. 6-346844 discloses a piston rotation-regulating structure in the swash plate type compressor. In the disclosed structure, rotation of each piston is regulated through sliding engagement between one or more rotation-regulating convex curved surfaces provided on the piston and the inner periphery of a compressor housing.
However, in this publication, even when the plurality of rotation-regulating convex curved surfaces are provided, the centers of curvature of them in a circumferential direction of the piston are located at the same position. Thus, it is equivalent to using only one rotation-regulating convex curved surface for regulating rotation of the piston. Further, since the curvature of the rotation-regulating convex curved surface is set greater than that of the inner periphery of the compressor housing, a line contact rather than a surface contact is formed therebetween to raise a problem in view of abrasion resistance.